Tibia shaft fractures: costly burden of nonunions

The economic impact of infection and/or nonunion on long-bone shaft fractures: a systematic review

Background

Long-bone fractures are a major cause of morbidity worldwide. These injuries are often complicated by infection or nonunion, which significantly affect patient quality of life and economic costs. Although studies have quantified the impact of these fractures, there is not a comprehensive review summarizing their economic and lifestyle costs.

Study Objective

This review summarized the impact of long-bone fracture infection and nonunion on health-related quality of life, as measured by utility scores, and both direct and indirect economic costs.

Methods

A systematic review was conducted using the following databases: PubMed, EMBASE, Web of Science, and the Cochrane Library. The search included terms related to long-bone fractures, infection, nonunion, cost, and utility. The search yielded 1267 articles, and after deduplication, 1144 were screened, yielding 116 articles for full-text review. Screening was conducted using Covidence and extraction using REDCap.

Results

Twenty-two articles met inclusion criteria, with the majority being from the United States and Europe. Most articles were retrospective studies, predominantly regarding the tibia. Fifteen articles contained cost data and 8 contained utility data, with 1 article containing both. Ten cost articles and 1 utility article contained infection data. 8 cost and all utility articles contained nonunion data. Infection ranged from 1.5 to 8.0 times the cost of an uncomplicated fracture. Nonunion ranged from 2.6 to 4.3 times the cost of an uncomplicated fracture. Utility data were variable and ranged from 0.62 to 0.66 for infection and 0.48-0.85 for nonunion.

Conclusions

Infection and nonunion after long-bone fractures are associated with large decreases in health-related quality of life and incur substantial costs to both patients and health care systems. The data presented in this review quantify these impacts and may serve useful for future economic analyses. In addition, this study highlights the dearth of high-quality literature on this important topic.

Promoting bone callus formation by taking advantage of the time-dependent fracture gap strain modulation

Delayed union and non-union of fractures continue to be a major problem in trauma and orthopedic surgery. These cases are challenging for the surgeon. In addition, these patients suffer from multiple surgeries, pain and disability. Furthermore, these cases are a major burden on healthcare systems. The scientific community widely agrees that the stability of fixation plays a crucial role in determining the outcome of osteosynthesis. The extent of stabilization affects factors like fracture gap strain and fluid flow, which, in turn, influence the regenerative processes positively or negatively. Nonetheless, a growing body of literature suggests that during the fracture healing process, there exists a critical time frame where intervention can stimulate the bone's return to its original form and function. This article provides a summary of existing evidence in the literature regarding the impact of different levels of fixation stability on the strain experienced by newly forming tissues. We will also discuss the timing and nature of this "window of opportunity" and explore how current knowledge is driving the development of new technologies with design enhancements rooted in mechanobiological principles.

Regulatory T cell-derived exosome mediated macrophages polarization for osteogenic differentiation in fracture repair

Refractory fracture presents an intractable challenge in trauma treatment. Selective polarization of macrophages as well as the recruitment of osteogenic precursor cells play key roles in osteogenic differentiation during fracture healing. Here we constructed regulatory T cell (Treg)-derived exosomes (Treg-Exo) for the treatment of fracture. The obtained exosomes displayed a spheroid shape with a hydrated particle size of approximately 130 nm. With further purification using CD39 and CD73 antibody-modified microfluidic chips, CD39 and CD73 specifically expressing exosomes were obtained. This kind of Treg-Exo utilized the ectonucleotidases of CD39 and CD73 to catalyze the high level of ATP in the fracture area into adenosine. The generated adenosine further promoted the selective polarization of macrophages. When interacting with mesenchymal stem cells (MSCs, osteogenic precursor cells), both Treg-Exo and Treg-Exo primed macrophages facilitated the proliferation and differentiation of MSCs. After administration in vivo, Treg-Exo effectively promoted fracture healing compared with conventional T cell-derived exosome. To further improve the delivery efficacy of exosomes and integrate multiple biological processes of fracture healing, an injectable hydrogel was fabricated to co-deliver Treg-Exo and stromal cell-derived factor 1 alpha (SDF-1α). With the dual effect of Treg-Exo for macrophage polarization and SDF-1α for MSC recruitment, the multifunctional hydrogel exerted a synergistic effect on fracture repair acceleration. This study provided a promising therapeutic candidate and synergistic strategy for the clinical treatment of fracture.

The integration of ortho-plastic limb salvage teams in the humanitarian response to violence-related open tibial fractures: evaluating outcomes in the Gaza Strip

BACKGROUND

Limb salvage by ortho-plastic teams is the standard protocol for treating open tibial fractures in high-income countries, but there's limited research on this in conflict settings like the Gaza Strip. This study assessed the clinical impact of gunshot-related open tibial fractures, compared patient management by orthopedic and ortho-plastic teams, and identified the risk factors for bone non-union in this context.

METHODS

A retrospective review of medical records was conducted on Gaza Strip patients with gunshot-induced-open tibial fractures from March 2018 to October 2020. Data included patient demographics, treatments, and outcomes, with at least one year of follow-up. Primary outcomes were union, non-union, infection, and amputation.

RESULTS

The study included 244 injured individuals, predominantly young adult males (99.2%) with nearly half (48.9%) having Gustilo-Anderson type IIIB fractures and more than half (66.8%) with over 1 cm of bone loss. Most patients required surgery, including rotational flaps and bone grafts with a median of 3 admissions and 9 surgeries. Ortho-plastic teams managed more severe muscle and skin injuries, cases with bone loss > 1 cm, and performed less debridement compared to other groups, though these differences were not statistically significant. Non-union occurred in 53% of the cases, with the ortho-plastic team having the highest rate at 63.6%. Infection rates were high (92.5%), but no significant differences in bone or infection outcomes were observed among the different groups. Logistic regression analysis identified bone loss > 1 cm, vascular injury, and the use of a definitive fixator at the first application as predictors of non-union.

CONCLUSIONS

This study highlights the severity and complexity of such injuries, emphasizing their significant impact on patients and the healthcare system. Ortho-plastic teams appeared to play a crucial role in managing severe cases. However, further research is still needed to enhance our understanding of how to effectively manage these injuries.

Effect of matrix material property on the composite tibia fracture plate: a biomechanical study

For the purpose of fixing tibia fractures, composite bone plates are suggested. Metal plates cause stress shielding, lessen the compression force at the fracture site, and have an impact on the healing process because they are significantly more rigid than bone. To prevent excessive shear strain and consequent instability at the fracture site, it is imperative to reduce stiffness in the axial direction without lowering stiffness in the transverse direction. Only a carefully crafted fiber reinforced composite with anisotropic properties will suffice to accomplish this. The purpose of the current study is to examine the impact of axial and shear movements at the fracture site on the fixing of metal and composite bone plates. After modeling the tibia with a 1 mm fracture gap, titanium plates, carbon/epoxy, carbon/PEEK, and carbon/UHMWPE composite bone plates were used to fix it. There are 6 holes on each of the 103 mm long plates. To determine the stresses and axial movement in the fracture site, anatomical 3D Finite Element (FE) models of the tibia with composite bone plates are built. The simulations that were run for various composite plate layouts and types give suggestions for selecting the best composite bone plate. Although the matrix material causes some variations in behaviors, most of the plates perform as well as or even better than metal plates. Thus, the appropriate composite combinations are recommended for a given fracture structure.

Impact of osteoporosis and osteoporosis medications on fracture healing: a narrative review

Antiresorptive medications do not negatively affect fracture healing in humans. Teriparatide may decrease time to fracture healing. Romosozumab has not shown a beneficial effect on human fracture healing.

BACKGROUND

Fracture healing is a complex process. Uncertainty exists over the influence of osteoporosis and the medications used to treat it on fracture healing.

METHODS

Narrative review authored by the members of the Fracture Working Group of the Committee of Scientific Advisors of the International Osteoporosis Foundation (IOF), on behalf of the IOF and the Société Internationale de Chirurgie Orthopédique et de Traumatologie (SICOT).

RESULTS

Fracture healing is a multistep process. Most fractures heal through a combination of intramembranous and endochondral ossification. Radiographic imaging is important for evaluating fracture healing and for detecting delayed or non-union. The presence of callus formation, bridging trabeculae, and a decrease in the size of the fracture line over time are indicative of healing. Imaging must be combined with clinical parameters and patient-reported outcomes. Animal data support a negative effect of osteoporosis on fracture healing; however, clinical data do not appear to corroborate with this. Evidence does not support a delay in the initiation of antiresorptive therapy following acute fragility fractures. There is no reason for suspension of osteoporosis medication at the time of fracture if the person is already on treatment. Teriparatide treatment may shorten fracture healing time at certain sites such as distal radius; however, it does not prevent non-union or influence union rate. The positive effect on fracture healing that romosozumab has demonstrated in animals has not been observed in humans.

CONCLUSION

Overall, there appears to be no deleterious effect of osteoporosis medications on fracture healing. The benefit of treating osteoporosis and the urgent necessity to mitigate imminent refracture risk after a fracture should be given prime consideration. It is imperative that new radiological and biological markers of fracture healing be identified. It is also important to synthesize clinical and basic science methodologies to assess fracture healing, so that a convergence of the two frameworks can be achieved.

Non-Union Treatment in the Foot, Ankle, and Lower Leg: A Multicenter Retrospective Study Comparing Conventional Treatment with the Human Allogeneic Cortical Bone Screw (Shark Screw®)

Addressing non-unions involves stabilizing the affected area through osteosynthesis and improving bone biology using bone grafts. However, there is no consensus on the optimal treatment method. This study aims to compare outcomes of non-union surgery using conventional treatment methods (metal hardware ± graft) versus osteosynthesis with the human allogeneic cortical bone screw (Shark Screw®) alone or in combination with a metallic plate. Thirty-four patients underwent conventional treatment, while twenty-eight cases received one or more Shark Screws®. Patient demographics, bone healing, time to bone healing, and complications were assessed. Results revealed a healing rate of 96.4% for the Shark Screw® group, compared to 82.3% for the conventionally treated group. The Shark Screw® group exhibited a tendency for faster bone healing (9.4 ± 3.2 vs. 12.9 ± 8.5 weeks, p = 0.05061). Hardware irritations led to six metal removals in the conventional group versus two in the Shark Screw® group. The Shark Screw® emerges as a promising option for personalized non-union treatment in the foot, ankle, and select lower leg cases, facilitating effective osteosynthesis and grafting within a single construct and promoting high union rates, low complications, and a rapid healing process.

Experimental and virtual testing of bone-implant systems equipped with the AO Fracture Monitor with regard to interfragmentary movement

Introduction: The management of fractured bones is a key domain within orthopedic trauma surgery, with the prevention of delayed healing and non-unions forming a core challenge. This study evaluates the efficacy of the AO Fracture Monitor in conjunction with biomechanical simulations to better understand the local mechanics of fracture gaps, which is crucial for comprehending mechanotransduction, a key factor in bone healing. Through a series of experiments and corresponding simulations, the study tests four hypotheses to determine the relationship between physical measurements and the predictive power of biomechanical models. Methods: Employing the AO Fracture Monitor and Digital Image Correlation techniques, the study demonstrates a significant correlation between the surface strain of implants and interfragmentary movements. This provides a foundation for utilizing one-dimensional AO Fracture Monitor measurements to predict three-dimensional fracture behavior, thereby linking mechanical loading with fracture gap dynamics. Moreover, the research establishes that finite element simulations of bone-implant systems can be effectively validated using experimental data, underpinning the accuracy of simulations in replicating physical behaviors. Results and Discussion: The findings endorse the combined use of monitoring technologies and simulations to infer the local mechanical conditions at the fracture site, offering a potential leap in personalized therapy for bone healing. Clinically, this approach can enhance treatment outcomes by refining the assessment precision in trauma trials, fostering the early detection of healing disturbances, and guiding improvements in future implant design. Ultimately, this study paves the way for more sophisticated patient monitoring and tailored interventions, promising to elevate the standard of care in orthopedic trauma surgery.

The local and systemic effects of immune function on fracture healing

The immune system plays an integral role in the regulation of cellular processes responsible for fracture healing. Local and systemic influences on fracture healing correlate in many ways with fracture-related outcomes, including soft tissue healing quality and fracture union rates. Impaired soft tissue healing, restricted perfusion of a fracture site, and infection also in turn affect the immune response to fracture injury. Modern techniques used to investigate the relationship between immune system function and fracture healing include precision medicine, using vast quantities of data to interpret broad patterns of inflammatory response. Early data from the PRECISE trial have demonstrated distinct patterns of inflammatory response in polytrauma patients, which thereby directly and indirectly regulate the fracture healing response. The clearly demonstrated linkage between immune function and fracture healing suggests that modulation of immune function has significant potential as a therapeutic target that can be used to enhance fracture healing.

Estimating the economic impact of complications after open tibial fracture: A secondary analysis of the pilot Gentamicin Open Tibia trial (pGO-Tibia)

Objectives

To estimate the indirect economic impact of tibial fractures and their associated adverse events (AEs) in Tanzania.

Design

A secondary analysis of the pilot Gentamicin Open (pGO)-Tibia randomized control trial estimating the indirect economic impact of suffering an AE, defined as a fracture-related infection (FRI) and/or nonunion, after an open tibial fracture in Tanzania.

Setting

The pGO-Tibia trial was conducted from November 2019 to August 2021 at the Muhimbili Orthopaedic Institute in Dar es Salaam, Tanzania.

Patients/Participants

One hundred adults with open tibial shaft fractures participated in this study.

Intervention

Work hours were compared between AE groups. Cost data were analyzed using a weighted-average hourly wage and converted into purchasing power parity-adjusted USD.

Main Outcome Measurements

Indirect economic impact was analyzed from the perspective of return to work (RTW), lost productivity, and other indirect economic and household costs. RTW was analyzed using a survival analysis.

Results

Half of patients returned to work at 1-year follow-up, with those experiencing an AE having a significantly lower rate of RTW. Lost productivity was nearly double for those experiencing an AE. There was a significant difference in the mean outside health care costs between groups. The total mean indirect cost was $2385 with an AE, representing 92% of mean annual income and an increase of $1195 compared with no AE. There were significantly more patients with an AE who endorsed difficulty affording household expenses postinjury and who borrowed money to pay for their medical expenses.

Conclusions

This study identified serious economic burden after tibial fractures, with significant differences in total indirect cost between those with and without an AE.

Level of Evidence

II.

Callus formation and bone remodeling in a tibial nonunion after minimal invasive percutaneous screw fixation followed by extracorporeal shockwave therapy 17-months after initial trauma - A case report

INTRODUCTION

The treatment of tibial nonunion is challenging and treatment may be conservative or surgical. Conservative strategies include functional braces and weight bearing, or focused extracorporeal shockwave therapy (fESWT).

CASE DESCRIPTION

A 45-year-old male patient sustained spiral tibial shaft fractures and was treated surgically within 24 hours after the initial accident with intramedullary nails. The tibial fracture was later classified as nonunion after 11 months. Radiologic evaluation 17 months after the initial trauma demonstrated clinical nonunion, and subsequently the patient was offered a conservative approach with fESWT to facilitate an increase in callus formation. The handpiece was fitted with a stand-off II (long), penetration depth of 15 mm. Three cycles were administered in month 17, 19 and 20 after baseline. Each cycle consisted of three treatments sessions spaced with 6-8 days apart, and consisted of 3000 to 4000 impulses each given at 0.25-0.84 mJ/mm2. The number of impulses and the power at the focus point varied according to the pain response.

OUTCOMES

The patient achieved union 23 months after fracture. A clinical important improvement was observed with both Lower Extremity Functional Scale (LEFS) (18-point difference) and Patient Specific Functional Scale (PSFS) (average: 4.7 points,) The "worst pain last 24 hours" was reduced by 5 points. These values express minimal clinically important difference (MCID) values in these functional patient-reported outcome measures.

CONCLUSION

This treatment strategy may be viable in a broader setting, including private practice physiotherapy thereby treating the patient in close proximity to the patient's everyday life.

The burden of long bone fracture and health system response in Malawi: A scoping review

OBJECTIVES

Fractures pose serious health and socioeconomic consequences for individuals, their families, and societies more broadly. In many low-resource settings, case fatality and long-term sequelae after a fracture remain high due to individual- and system-level barriers affecting timely access to care. This scoping review explored the burden of fractures in Malawi using long bone fracture (LBF) as a case study by examining the epidemiology of these injuries, their consequences, and the accessibility of quality healthcare. Our aim is to not only describe the scale of the issue but to identify specific interventions that can help address the challenges faced in settings with limited resources and healthcare budgets.

METHODS

A scoping review methodology was adopted with a narrative synthesis of results. We searched five databases to identify relevant literature and applied the "Three Delays" model and the WHO's Building Blocks Framework to analyse findings on the accessibility of fracture care.

RESULTS

Fractures most often occurred among young males, with falls being the leading cause, constituting between 5 and 35 % of the total burden of injuries. Fractures were typically managed without surgery despite consistent local evidence showing surgical treatment was superior to conservative management in terms of length of hospital stay and bone healing. Poor functional, economic, and social outcomes were noted in fracture patients, especially after conservative treatment. A lack of trust in the health system, financial barriers, poor transport, and road infrastructure, and interfacility transfers were identified as barriers to care-seeking. Factors challenging the provision of appropriate care included governance issues, poor health infrastructure, financial constraints, and shortage of supplies and human resources.

CONCLUSIONS

To the best of our knowledge, this review represents the first comprehensive examination of the state of LBF and the health system's response in Malawi. The findings underscore the pressing need for a national trauma registry to accurately determine the actual burden of injuries and support a tailored approach to fracture care in Malawi. It is further evident that the health system in Malawi must be strengthen across all six building blocks to address obstacles to equitable access to high-quality fracture care.

Principles and Evaluation of Bony Unions

Nonunion is a common and costly problem. Unfortunately, there is no widely agreed upon and standardized definition for nonunion. The evaluation of bony union should start with a thorough history and physical examination. The clinician should consider patient-dependent as well as patient-independent characteristics that may influence the rate of healing and evaluate the patient for physical examination findings suggestive of bony union and infection. Radiographs and clinical examination can help confirm a diagnosis of union. When the diagnosis is in doubt, however, advanced imaging modalities as well as laboratory studies can help a surgeon determine when further intervention is necessary.

Advances with Platelet-Rich Plasma for Bone Healing

Despite significant advances in the understanding and delivery of osteosynthesis, fracture non-union remains a challenging clinical problem in orthopaedic surgery. To bridge the gap, basic science characterization of fracture healing provides a platform to identify and target biological strategies to enhance fracture healing. Of immense interest, Platelet-rich plasma (PRP) is a point of care orthobiologic that has been extensively studied in bone and soft tissue healing given its relative ease of translation from the benchtop to the clinic. The aim of this narrative review is to describe and relate pre-clinical in-vitro and in-vivo findings to clinical observations investigating the efficacy of PRP to enhance bone healing for primary fracture management and non-union treatment. A particular emphasis is placed on the heterogeneity of PRP preparation techniques, composition, activation strategies, and delivery. In the context of existing data, the routine use of PRP to enhance primary fracture healing and non-union management cannot be supported. However, it is acknowledged that extensive heterogeneity of PRP treatments in clinical studies adds obscurity; ultimately, refinement (and consensus) of PRP treatments for specific clinical indications, including repetition studies are warranted.

Circular external fixation for revision of failed tibia internal fixation

BACKGROUND

The management of failed tibial fracture fixation remains a challenge for orthopaedic surgeons. This study investigate the utility and outcomes of circular external fixation in the management of failed internal fixation of tibial fractures.

METHODS

Retrospective review of a prospectively collected database of a complex limb reconstruction unit at a major trauma centre was done during December 2022. Patients with failed internal fixation of tibial fracture who underwent revision surgery with circular external fixation frame were included.

RESULTS

20 patients with a mean age of 47.8 ± 16.5 years (range: 15-69) were included. Fourteen (70.0%) patients had failed plate and screws fixations, and the remaining six (30.0%) failed intramedullary nail fixation. The most common indication for revision surgery was development of early postoperative surgical site infection (5 patients; 25.0%). The mean duration of frame treatment was 199.5 ± 80.1 days (range = 49-364), while the mean follow-up duration following frame removal was 3.2 ± 1.8 years (range = 2-8). The overall union rate in this series was 100%; and all infected cases had complete resolution from infection. The total number of complications was 11, however, only two complications required surgical intervention. The most common complications reported were pin site infection (6; 30.0%) and limb length discrepancy of 2 cm (2; 10.0%).

CONCLUSIONS

Circular external fixation is a reliable surgical option in the treatment of failed internal fixation of tibia fractures. This technique can provide limb salvage in complex infected and noninfected cases with a high union rate and minimal major complications.

Effect of Bushen Tiansui Decoction on Delayed Fracture Healing: A Systematic Review and Meta-analysis

This review aimed to validate the therapeutic potential of Bushen Tiansui decoction (BSTSD), a traditional Chinese formulation, in treating delayed union of fractures. Comprehensive database searches identified randomized controlled trials up to September 13, 2022, assessing BSTSD's efficacy in delayed fracture healing. Outcomes were bone metabolism indexes and Harris hip scores. Quality and risk assessments were conducted using the Cochrane Collaboration's tools. Data were analyzed using RevMan software, with sensitivity analysis through Stata. BSTSD significantly improved bone GLA protein (SMD=1.76, P<0.00001) and alkaline phosphatase (SMD=1.31, P<0.00001). Additionally, Harris hip scores for pain, function, deformity, and motion showed marked improvement. BSTSD treatment also demonstrated enhanced clinical efficiency (RR=1.27, P<0.00001) with fewer complications. Sensitivity analyses indicated consistent results. BSTSD shows promise in treating delayed fracture unions, yet conclusions necessitate further high-quality research for validation.

Can "Aseptic" Looking TIBIA Non-union be Result of an Unrecognized Subclinical Infection?

Introduction

The usual cause of a distal tibial fracture is a high-energy trauma. Although multiple options are available for their treatment such as intramedullary nailing, open plating, and external fixator, each of these options might result in a non-union. Knowing the type of non-union not only allows us to guess the cause but also directs us toward the best possible treatment. Despite this, we might still get surprises on the operating table due to pre-operative misdiagnosis.

Case Report

Reporting a case of a 42-year-old male with a 15-month-old left distal tibia non-union. The index injury was a grade 1 distal third tibia fibula fracture which was fixed with a plate and screws 15 months back. All the clinical and biochemical signs hinted toward the diagnosis of an aseptic non-union and the treatment was planned accordingly. However, intraoperative findings were much different due to which the surgeons had to improvise and change the intervention to an antibiotic-coated nail.

Conclusion

Although each variety of non-union has its set of signs and symptoms, they can be misleading. Different etiologies can coexist making it difficult to give a perfect pre-operative diagnosis and management. Non-unions, especially in the tibia, thus need meticulous understanding of the underlying disease process and extensive treatment strategies.

Employing direct electromagnetic coupling to assess acute fracture healing: An ovine model assessment

OBJECTIVES

This study explored the efficacy of collecting temporal fracture site compliance data via an advanced direct electromagnetic coupling (DEC) system equipped with a Vivaldi-type antenna, novel calibration technique, and multi-antenna setup (termed maDEC) as an approach to monitor acute fracture healing progress in a translational large animal model. The overarching goal of this approach was to provide insights into the acute healing dynamics, offering a promising avenue for optimizing fracture management strategies.

METHODS

A sample of twelve sheep, subjected to ostectomies and intramedullary nail fixations, was divided into two groups, simulating normal and impaired healing scenarios. Sequential maDEC compliance or stiffness measurements and radiographs were taken from the surgery until euthanasia at four or eight weeks and were subsequently compared with post-sacrifice biomechanical, micro-CT, and histological findings.

RESULTS

The results showed that the maDEC system offered straightforward quantification of fracture site compliance via a multiantenna array. Notably, the rate of change in the maDEC-measured bending stiffness significantly varied between normal and impaired healing groups during both the 4-week (p = 0.04) and 8-week (p = 0.02) periods. In contrast, radiographically derived mRUST healing measurements displayed no significant differences between the groups (p = 0.46). Moreover, the cumulative normalized stiffness maDEC data significantly correlated with post-sacrifice mechanical strength (r2 = 0.80, p < 0.001), micro-CT measurements of bone volume fraction (r2 = 0.60, p = 0.003), and density (r2 = 0.60, p = 0.003), and histomorphometric measurements of new bone area fraction (r2 = 0.61, p = 0.003) and new bone area (r2 = 0.60, p < 0.001).

CONCLUSIONS

These data indicate that the enhanced maDEC system provides a non-invasive, accurate method to monitor fracture healing during the acute healing phase, showing distinct stiffness profiles between normal and impaired healing groups and offering critical insights into the healing process's progress and efficiency.

Reappraisal of clinical trauma trials: the critical impact of anthropometric parameters on fracture gap micro-mechanics-observations from a simulation-based study

The evidence base of surgical fracture care is extremely sparse with only few sound RCTs available. It is hypothesized that anthropometric factors relevantly influence mechanical conditions in the fracture gap, thereby interfering with the mechanoinduction of fracture healing. Development of a finite element model of a tibia fracture, which is the basis of an in silico population (n = 300) by systematic variation of anthropometric parameters. Simulations of the stance phase and correlation between anthropometric parameters and the mechanical stimulus in the fracture gap. Analysis of the influence of anthropometric parameters on statistical dispersion between in silico trial cohorts with respect to the probability to generate two, with respect to anthropometric parameters statistically different trial cohorts, given the same power assumptions. The mechanical impact in the fracture gap correlates with anthropometric parameters; confirming the hypothesis that anthropometric factors are a relevant entity. On a cohort level simulation of a fracture trial showed that given an adequate power the principle of randomization successfully levels out the impact of anthropometric factors. From a clinical perspective these group sizes are difficult to achieve, especially when considering that the trials takes advantage of a "laboratory approach ", i.e. the fracture type has not been varied, such that in real world trials the cohort size have to be even larger to level out the different configurations of fractures gaps. Anthropometric parameters have a significant impact on the fracture gap mechanics. The cohort sizes necessary to level out this effect are difficult or unrealistic to achieve in RCTs, which is the reason for sparse evidence in orthotrauma. New approaches to clinical trials taking advantage of modelling and simulation techniques need to be developed and explored.

Osteogenesis Stimulator Devices Reduce Surgical Intervention, Opioid Utilization, and Overall Costs in Patients with Fracture Nonunions

Background

Approximately 10% of fractures result in delayed union or nonunion. These cases result in pain and disability as well as increased utilization of healthcare resources such as pain medication, physical therapy, and subsequent surgery. Osteogenesis stimulator devices are a safe and low-cost, non-invasive option to aid healing in nonunion cases.

Objective

Study objectives aimed to evaluate real-world data of osteogenesis stimulator device usage in a variety of healthcare utilization endpoints including surgical intervention for nonunion, pain medication use, and overall healthcare costs. Data were stratified into three groups: the Stim Device group and the No Stim and Surgical control groups.

Methods

A retrospective analysis of a large claims-based database was conducted. The database was queried for adult patients having a diagnosis of nonunion, with evidence of a prior fracture in the previous 180 days (n = 11,010). The osteogenesis stimulator group (Stim Device group, n = 1,628) was defined as those patients having at least one claim for an osteogenesis stimulator in the period 90 to 180 days following fracture and up to 60 days following the nonunion diagnosis. The control group (No Stim group, n = 9,382) had a nonunion diagnosis with evidence of a fracture in the prior 180 days but did not receive a device. A total of 1,751 patients from the No Stim group were sub-grouped into surgical/operative controls (No Stim - Surgical group).

Results

Stim Device patients showed lower rates of surgical intervention for their bone nonunion compared to the No Stim patients (214/1,628, 13.1% vs. 1,751/9,382, 18.7%, p < 0.001). Stim Device patients had lower rates of opioid utilization post-index compared to No Stim patients (948/1,628, 58.2% vs. 6,359/9,382, 67.8%, p < 0.001). Overall healthcare costs were significantly reduced in the Stim Device group ($21,654) compared with No Stim ($29,101; p < 0.001) and Surgical ($35,914; p < 0.001) control groups.

Conclusion

The results show that bone growth stimulator devices have a positive individual and societal impact on treating patients with fracture nonunions.

Digital monitoring of weight-bearing improves success rates and reduces complications in lower extremity surgeries

The aim of this study is to develop a digital monitoring system to track weight and evaluate its impact on postoperative outcomes after lower extremity surgeries (LES). This parallel randomized controlled trial enrolled 266 patients who underwent LES (fracture or joint replacement) at our medical center between March 11, 2022, and January 10, 2023. Patients were randomly assigned to the intervention and control groups in a 1:1 ratio. The intervention group (n=116) used a cane and shoes equipped with a weight-bearing system after lower limb surgery, while the control group (n=116) used a simple cane and shoes without a weight-bearing system. The primary outcomes included callus formation, duration of union, and success rate of union in the two groups. The intervention group had a significantly higher rate of complete surgical success than the control group (93.9% vs. 79.3%, p=0.001). The intervention group also had a significantly lower risk of non-union than the control group (OR: 2.33, 95% CI: 1.14, 3.48, p=0.001). The mean duration of surgery until the time of union and the meantime of callus formation was significantly lower in the intervention group (p=0.01). The use of a digital monitoring system for weighing in LES significantly increased the success rate and reduced post-operative complications. Therefore, incorporating this system can enhance the rehabilitation process and prevent revision surgeries in patients with LES.

Orthopedic surgeons and physical therapists differ regarding rehabilitative needs after lower extremity fracture repair

BACKGROUND

Little evidence is available to guide physical therapy (PT) following lower extremity fracture repair distal to the hip. As such, variability has been reported in the way PT is utilized post-operatively. Examination of current practice by orthopedic surgeons (OS) and physical therapists is needed to inform clinical practice guidelines in this area.

OBJECTIVE

To describe current PT referral practices among OS, identify patient and clinical factors that affect PT referral, and examine differences between OS and physical therapists with regard to visit frequency, duration, and use of specific PT interventions.

METHODS

Provider surveys.

RESULTS

Surveys were completed by 100 OS and 347 physical therapists. Over half (54%) of OS reported referring "most patients" to PT and identified joint stiffness and strength limitations as top reasons for PT referral. Over 80% of OS and physical therapists indicated that joint stiffness, strength limitations, and patients' functional goals affected their recommendations for PT visit frequency. More physical therapists than OS reported that pain severity (55% vs 25%, p < .001), maladaptive pain behaviors (64% vs. 33%, p < .001), and patient self-efficacy (70% vs. 49%, p = .003) affected their visit frequency recommendations. While OS recommended more frequent PT for patients with peri-articular fractures, fracture type had minimal impact on the visit frequencies recommended by physical therapists.

CONCLUSION

OS and physical therapists consider similar physical impairments when determining the need for PT and visit frequencies, however, physical therapists consider pain and psychosocial factors more often, with OS focusing more on injury type.

Association of Fracture Location and Pattern With Nonunion or Malunion in Tibia Fractures Managed With Intramedullary Nailing: A Retrospective Study

Background and objective Extra-articular fractures of the tibia are common orthopedic injuries that are frequently treated with rigid intramedullary nailing. Fracture location and pattern may increase the risk of nonunion or malunion in fractures managed with intramedullary nails. This study aimed to assess the relationship between fracture pattern and location with malunion and nonunion. The primary objective was to evaluate the influence of fracture location and pattern on adverse clinical outcomes such as nonunion, delayed union, and malunion in tibial shaft fractures that are treated operatively with rigid intramedullary nails. Methodology This was a retrospective cross-sectional study conducted on patients operated in a tertiary care center in the Kingdom of Bahrain. The study included patients who sustained tibia shaft fractures and were subsequently operated with intramedullary of the tibia. The primary endpoint was the rate of adverse outcomes associated with fracture patterns. Fracture characteristics were to determine which fracture patterns healed well with intramedullary nailing and which fractures ended up with malunion or nonunion and would likely benefit from additional measures to augment the nail fixation and help encourage union. Results One hundred and eighty-nine patients were included in the study. The level of associated fibula fracture was significantly associated with an increased risk of nonunion and malunion (P = 0.0034, P = 0.001). The presence of a concomitant distal fibula fracture in association with tibia fractures increased the odds of nonunion (odds ratio [OR] = 4.871, P = 0.033, confidence interval [CI] = 1.133-20.948). Conclusions The level and pattern of some tibia and fibula fractures were associated with nonunion, malunion, and delayed union. Further studies with more robust follow-up are needed to examine these findings in greater detail.

Multicenter consensus statements on the use of low-intensity pulsed ultrasound (LIPUS) in Hand Surgery

OBJECTIVE

The purpose of this agreement was to establish consensus statements on the use of low-intensity pulsed ultrasound (LIPUS) in hand surgery.

METHODS

Based on Delphi consensus methodology, a preliminary list of questions on the use of LIPUS in hand surgery was developed by an interdisciplinary team of hand and plastic surgeons as well as psychologists and experts from communications science. Based on these, questionnaires were invented and a total of three Delphi rounds have been conducted. Delphi panelists consisted of 11 German hand surgeons with a mean experience in hand surgery of 15 years (7-23 years). Questions and statements were revised during this process, resulting in a consensus at the end of round three.

RESULTS

After three Delphi rounds, the following recommendations could be derived. LIPUS can be applied for impaired fracture healing of the digits, metacarpals, carpal bones as well as a prophylactic procedure in order to avoid further revision surgery. LIPUS therapy can be useful in addition to revision surgery for delayed union and non-unions. In the case of certain risk factors (replantation, revascularization, osteoporosis, smoking), it can be applied directly postoperatively in order to prevent impaired fracture healing. It should be applied for 90-120 days.

CONCLUSION

There is a consensus among German hand surgeons, when and how LIPUS can be applied for improving fracture healing of the hand. Randomized controlled trials with direct comparison of fracture treatment with and without LIPUS are needed to support these statements with objective data.

Gentamicincoated tibial nail is an effective prevention method for fracture-related infections in open tibial fractures

Fracture-related infection (FRI) is a common complication following open tibia fracture (OTF), especially in patients with high-energy trauma or comorbidities. The use of gentamicin-coated nail (GCN) has been proposed as a local adjuvant to prevent FRI in high-risk patients.

HYPOTHESIS

The incidence of FRI is expected to be lower in OTF treated with a GCN, alongside with no detrimental effects on fracture healing time.

OBJECTIVES

This study aimed to evaluate the effectiveness of GCNs as a definitive fixation method and prophylaxis for FRI in OTFs. Secondary outcomes included non-union rates and time to healing.

METHODS

The study design was a mixed cohort, including a prospective group of patients treated with GCN (Expert Tibial Nail PROtect™, Depuy Synthes, Johnson&Johnson Company Inc, New Jersey, USA) and a retrospectively evaluated group treated with non-gentamicin-coated nail (NGCN). Patients with at least 12 months of follow-up were included. The treatment protocol consisted of timely administration of antibiotics, surgical debridement, and early soft-tissue coverage. Exclusion criteria included protocol infringement, traumatic amputation, and loss of follow-up. Statistical analysis was performed using Stata v14.0, with a significance level of p < 0.05.

RESULTS

The study included 243 patients, 104 in GCN group and 139 NGCN group. External Fixator use was higher in the NGCN group, but this did not significantly affect the FRI rate. GCN use was associated with a significantly lower incidence of FRI (2.88% GCN group vs. 15.83% NGCN group, OR 0.16, p < 0.01). Furthermore, GCN use was found to be a protective factor against tibial non-union (OR 0.41, p = 0.03). There were no adverse effects attributed to locally administered gentamycin. The NGCN cohort had a higher incidence of polytrauma, although the difference was not statistically significant. A longer time to heal as well as more FRI and Non-union according to the progression in Gustilo-Anderson classification was observed in the GCN group.

CONCLUSION

Our findings suggest that GCN is an effective prophylactic method to reduce the risk of FRI in open tibial fractures at 12-month follow-up, as well as, probably derived from this protective effect, leading to lower fracture consolidation times when compared with cases treated without GCN.

Use of Conditionally Essential Amino Acids and the Economic Burden of Postoperative Complications After Fracture Fixation: Results from a Cost Utility Analysis

Objective

To measure the economic impact of conditionally essential amino acids (CEAA) among patients with operative treatment for fractures.

Methods

A decision tree model was created to estimate changes in annual health care costs and quality of life impact due to complications after patients underwent operative treatment to address a traumatic fracture. The intervention of interest was the use of CEAA alongside standard of care as compared to standard of care alone. Patients were required to be aged ≥18 and receive the surgery in a US Level 1 trauma center. The primary outcomes were rates of post-surgical complications, changes in patient quality adjusted life years (QALYs), and changes in cost. Cost savings were modeled as the incremental costs (in 2022 USD) of treating complications due to changes in complication rates.

Results

The per-patient cost of complications under CEAA use was $12,215 compared to $17,118 under standard of care without CEAA. The net incremental cost savings per patient with CEAA use was $4902, accounting for a two-week supply cost of CEAA. The differences in quality-adjusted life years (QALYs) under CEAA use and no CEAA use was 0.013 per person (0.739 vs 0.726). Modeled to the US population of patients requiring fracture fixations in trauma centers, the total value of CEAA use compared to no CEAA use was $316 million with an increase of 813 QALYs per year. With a gain of 0.013 QALYs per person, valued at $150,000, and the incremental cost savings of $4902 resulted in net monetary benefit of $6852 per patient. The incremental cost-effectiveness ratio showed that the use of CEAA dominated standard of care.

Conclusion

CEAA use after fracture fixation surgery is cost saving. Level of Evidence: Level 1 Economic Study.

Risk factors and healthcare costs associated with long bone fracture non-union: a retrospective US claims database analysis

BACKGROUND

Few contemporary US-based long bone non-union analyses have recently been published. Our study was designed to provide a current understanding of non-union risks and costs, from the payers' perspective.

METHODS

The Merative™ MarketScan® Commercial Claims and Encounters database was used. Patients with surgically treated long bone (femur, tibia, or humerus) fractures in the inpatient setting, from Q4 2015 to most recent, were identified. Exclusion criteria included polytrauma and amputation at index. The primary outcome was a diagnosis of non-union in the 12 and 24 months post-index. Additional outcomes included concurrent infection, reoperation, and total healthcare costs. Age, gender, comorbidities, fracture characteristics, and severity were identified for all patients. Descriptive analyses were performed. Crude and adjusted rates of non-union (using Poisson regressions with log link) were calculated. Marginal incremental cost of care associated with non-union and infected non-union and reoperation were estimated using a generalized linear model with log link and gamma distribution.

RESULTS

A total of 12,770, 13,504, and 4,805 patients with femoral, tibial, or humeral surgically treated fractures were identified, 74-89% were displaced, and 18-27% were comminuted. Two-year rates of non-union reached 8.5% (8.0%-9.1%), 9.1% (8.6%-9.7%), and 7.2% (6.4%-8.1%) in the femoral, tibial, and humeral fracture cohorts, respectively. Shaft fractures were at increased risk of non-union versus fractures in other sites (risk ratio (RR) in shaft fractures of the femur: 2.36 (1.81-3.04); tibia: 1.95 (1.47-2.57); humerus: 2.02 (1.42-2.87)). Fractures with severe soft tissue trauma (open vs. closed, Gustilo III vs. Gustilo I-II) were also at increased risk for non-union (RR for Gustilo III fracture (vs. closed) for femur: R = 1.96 (1.45-2.58), for tibia: 3.33 (2.85-3.87), RR for open (vs. closed) for humerus: 1.74 (1.30-2.32)). For all fractures, younger patients had a reduced risk of non-union compared to older patients. For tibial fractures, increasing comorbidity (Elixhauser Index 5 or greater) was associated with an increased risk of non-union. The two-year marginal cost of non-union ranged from $33K-$45K. Non-union reoperation added $16K-$34K in incremental costs. Concurrent infection further increased costs by $46K-$86K.

CONCLUSIONS

Non-union affects 7-10% of surgically treated long bone fracture cases. Shaft and complex fractures were at increased risk for non-union.

[Three-dimensional analysis of posttraumatic tibial shaft malunion and correction based on the healthy, contralateral leg]

OBJECTIVE

Three-dimensional (3D) analysis and implementation with patient-specific cutting and repositioning blocks enables correction of complex tibial malunions. Correction can be planned using the contralateral side or a statistical model. Patient-specific 3D-printed cutting guide blocks enable a precise osteotomy and reduction guide blocks help to achieve anatomical reduction. Depending on the type and extent of correction, fibula osteotomy may need to be considered to achieve the desired reduction.

CONTRAINDICATIONS

a) Poor soft tissue (flap surgery, adherent skin in field of operation); b) infection; c) peripheral artery disease (stage III and IV classified according to Fontaine, critical transcutaneous oxygen partial pressure, TcPO2); d) general contraindication to surgery.

SURGICAL TECHNIQUE

Before surgery, a 3D model of both lower legs is created based on computed tomography (CT) scans. Analysis of the deformity based on the contralateral side in a 3D computer model (CASPA) and planning of the osteotomy. If the contralateral side also has a deformity, a statistical model can be used. Printing of patient-specific guides made of nylon (PA2200) for the osteotomy and reduction. Surgery is performed in supine position, antibiotic prophylaxis, thigh tourniquet, which is used as needed. Ventrolateral approach to the tibia. Attachment of the patient-specific osteotomy guide, performance of the osteotomy. Reduction using the guide. Fibula osteotomy through a lateral approach is performed if the reduction of the tibia is hindered by the fibula. This can be performed freehand or with patient-specific guides. Wound closure.

POSTOPERATIVE MANAGEMENT

Compartment monitoring. Passive mobilization of the ankle in the cast as soon as the wound healing has progressed. Partial weightbearing in a lower leg cast for at least 6-12 weeks, depending on the routinely performed radiographic assessment 6 weeks postoperatively. Thromboprophylaxis with low molecular weight heparin until cast removal.

RESULTS

Patient-specific correction of malunions are generally good. This could be confirmed for distal tibial corrections. For tibial shaft deformities, the final results are still pending. Preliminary results, however, show good feasibility with a pseudarthrosis rate of 10% without postoperative infection.

Parathyroid hormone therapy improves MRSA-infected fracture healing in a murine diabetic model

Introduction

Diabetes mellitus (DM) impairs fracture healing and is associated with susceptibility to infection, which further inhibits fracture healing. While intermittent parathyroid hormone (1-34) (iPTH) effectively improves fracture healing, it is unknown whether infection-associated impaired fracture healing can be rescued with PTH (teriparatide).

Methods

A chronic diet-induced type 2 diabetic mouse model was used to yield mice with decreased glucose tolerance and increased blood glucose levels compared to lean-fed controls. Methicillin-resistant Staphylococcus aureus (MRSA) was inoculated in a surgical tibia fracture model to simulate infected fracture, after which mice were treated with a combination of antibiotics and adjunctive teriparatide treatment. Fracture healing was assessed by Radiographic Union Scale in Tibial Fractures (RUST), micro-computed tomography (μCT), biomechanical testing, and histology.

Results

RUST score was significantly poorer in diabetic mice compared to their lean nondiabetic counterparts. There were concomitant reductions in micro-computed tomography (μCT) parameters of callus architecture including bone volume/total volume, trabecular thickness, and total mineral density in type 2 diabetes mellitus (T2DM) mice. Biomechanicaltesting of fractured femora demonstrated diminished torsional rigidity, stiffness, and toughness to max torque. Adjuvant teriparatide treatment with systemic antibiotic therapy improved numerous parameters of bone microarchitecture bone volume, increased connectivity density, and increased trabecular number in both the lean and T2DM group. Despite the observation that poor fracture healing in T2DM mice was further impaired by MRSA infection, adjuvant iPTH treatment significantly improved fracture healing compared to antibiotic treatment alone in infected T2DM fractures.

Discussion

Our results suggest that teriparatide may constitute a viable adjuvant therapeutic agent to improve bony union and bone microarchitecture to prevent the development of septic nonunion under diabetic conditions.

WEDGE FRAGMENT VARIATIONS OF TIBIAL SHAFT FRACTURES WITH INTRAMEDULLARY NAILING

Introduction

Tibial shaft fracture is the most common long-bone fracture, and the standard treatment is intramedullary (IM) nail fixation. Regardless of the development of this technique pseudoarthrosis remains prevalent.

Objectives

Evaluate the correlation between wedge fragment size and displacement, displacement of the main fragments of the 42B2 type, and pseudoarthrosis incidence.

Methods

We retrospectively assessed all patients with 42B2 type fracture treated with IM nailing between January, 2015 and December, 2019. Six radiographic parameters were defined for preoperative radiographs in the anteroposterior (AP) and lateral views. Another six parameters were defined for postoperative radiographs at three, six, and 12 months. The Radiographic Union Score for Tibial Fractures score was used to assess bone healing.

Results

Of 355 patients with tibial shaft fractures, 51 were included in the study. There were 41 (82.0%) male patients, with a mean age of 36.7 years, 37 (72.5%) had open fractures, and 28 (54.9%) had associated injuries. After statistical analysis, the factors that correlated significantly with nonunion were wedge height > 18 mm, preoperative translational displacement of the fracture in the AP view > 18 mm, and final distance of the wedge in relation to its original anatomical position after IM nailing > 5 mm.

Conclusion

Risk factors for nonunion related to the wedge and42B2 fracture are wedge height > 18 mm, initial translation in the AP view of the fracture > 18 mm, and distance > 5 mm of the wedge from its anatomical position after IM nailing. Evidence level III; Retrospective comparative study .

Comparison of mini-open reduction and autologous bone grafting with closed reduction and intramedullary device insertion for tibial shaft fractures: a retrospective study

BACKGROUND

We compared the clinical efficacy of mini-open reduction and autologous bone grafting (G_M) and closed reduction (G_C) using intramedullary nailing for the treatment of tibial shaft fractures.

METHODS

This retrospective study included 70 tibial shaft fractures treated with G_M or G_C between January 2018 and December 2021. The demographic characteristics and clinical outcomes were compared between the two treatment methods.

RESULTS

This study included 70 patients who were followed-up for 12.4 months. In total, 31 and 39 patients were treated with G_M and G_C, respectively. The operative duration was significantly shorter for G_M (95.2 ± 19.3 min) than for G_C (105.5 ± 22.2 min, p = 0.0454). The number of radiation times was significantly lower for G_M (14.7 ± 6.3) than for G_C (22.2 ± 9.2, p < 0.005). There were no statistically significant differences between the groups in terms of the wound complication or infection rates. The malunion and nonunion rates were high after G_C than after G_M, but there are no significant differences between the groups.

CONCLUSIONS

Closed reduction and intramedullary nailing remains the first choice for tibial shaft fractures. G_M is a safe and effective treatment worth considering. Future prospective randomized controlled trials are warranted.

Is human immunodeficiency virus a risk factor for the development of nonunion?-a case-control study

Objective

Human immunodeficiency virus (HIV) infection has been suggested to be associated with an increased risk of the development of nonunion after a fracture. This prospective matched case-control study in South Africa investigated common risk factors, including HIV status, that influence the development of a nonunion after a femur or tibia fracture.

Methods

Adult participants (cases) with established nonunions of the femur or tibia shaft were recruited over a 16-month period, between December 2017 and April 2019. They were matched for (1) age; (2) sex; (3) fracture site; and (4) fracture management type, with "control" participants who progressed to fracture union within 6 months of injury. All participants were tested for HIV. Multivariable logistic regression models were constructed to investigate associations between known risk factors for the development of nonunion and impaired fracture healing.

Results

A total of 57 cases were matched with 57 "control" participants (44/57 male, 77.2% vs. 13/57 female, 22.8%, median age 36 years). HIV status was not associated with the development of nonunion after the management of tibia and femur fractures, on both univariate (odds ratio, 0.40; confidence interval, 0.10-1.32; P = 0.151) or multivariable (odds ratio, 0.86; confidence interval, 0.18-3.73; P = 0.831) analysis. No other confounding factors were shown to have any statistically significant impact on the odds of developing nonunion in this study cohort.

Conclusion

This study demonstrates that HIV does not seem to increase the risk of the development of nonunion and HIV-positive individuals who sustain a fracture can be managed in the same manner as those who are HIV negative.

Single-cell RNAseq provides insight into altered immune cell populations in human fracture nonunions

Nonunion describes bone fractures that fail to heal, resulting in the fracture callus failing to fully ossify or, in atrophic cases, not forming altogether. Fracture healing is regulated, in part, by the balance of proinflammatory and anti-inflammatory processes occurring within the bone marrow and surface cell populations. We sought to further understand the role of osteoimmunology (i.e., study of the close relationship between the immune system and bone) by examining immune cell gene expression via single-cell RNA sequencing of intramedullary canal tissue obtained from human patients with femoral nonunions. Intramedullary canal tissue samples obtained by reaming were collected at the time of surgical repair for femur fracture nonunion (n = 5) or from native bone controls when harvesting autologous bone graft (n = 4). Cells within the samples were isolated and analyzed using the Chromium Single-Cell System (10x Genomics Inc.) and Illumina sequencers. Twenty-three distinct cell clusters were identified, with higher cell proportions in the nonunion samples for monocytes and CD14 + dendritic cells (DCs), and lower proportions of T cells, myelocytes, and promyelocytes in nonunion samples. Gene expression differences were identified in each of the cell clusters from cell types associated with osteoimmunology, including CD14 + DC, monocytes, T cells, promyelocytes, and myelocytes. These results provide human-derived gene profiles that can further our understanding of pathways that may be a cause or a consequence of nonunion, providing the clinical rationale to focus on specific components of osteoimmunology. Clinical significance: The novel single-cell approach may lead to clinically relevant diagnostic biomarkers during earlier stages of nonunion development and/or investigation into therapeutic options.

Biomaterial scaffolds regulate macrophage activity to accelerate bone regeneration

Bones are important for maintaining motor function and providing support for internal organs. Bone diseases can impose a heavy burden on individuals and society. Although bone has a certain ability to repair itself, it is often difficult to repair itself alone when faced with critical-sized defects, such as severe trauma, surgery, or tumors. There is still a heavy reliance on metal implants and autologous or allogeneic bone grafts for bone defects that are difficult to self-heal. However, these grafts still have problems that are difficult to circumvent, such as metal implants that may require secondary surgical removal, lack of bone graft donors, and immune rejection. The rapid advance in tissue engineering and a better comprehension of the physiological mechanisms of bone regeneration have led to a new focus on promoting endogenous bone self-regeneration through the use of biomaterials as the medium. Although bone regeneration involves a variety of cells and signaling factors, and these complex signaling pathways and mechanisms of interaction have not been fully understood, macrophages undoubtedly play an essential role in bone regeneration. This review summarizes the design strategies that need to be considered for biomaterials to regulate macrophage function in bone regeneration. Subsequently, this review provides an overview of therapeutic strategies for biomaterials to intervene in all stages of bone regeneration by regulating macrophages.

Butterfly fragments in diaphyseal tibial fractures heal unpredictably: Should we be adopting other strategies for these high risk fractures?

INTRODUCTION

The natural history of diaphyseal tibial butterfly fragments is poorly documented. Numerous studies have analyzed risk factors for nonunions in the tibial shaft with known factors including Gustilo classification, ASA class, and cortical contact. However, the healing potential and ideal management of nonsegmental butterfly fragments in this setting remains unknown. The aim of this study was to determine the nonunion rate of diaphyseal tibial fractures with a butterfly fragment.

METHODS

A performed a retrospective review of patients at a single academic Level 1 Trauma Center from 2000-2020 who underwent intramedullary nailing of tibial shaft fractures. Those with non-segmental butterfly fragments (OTA/AO: 42-B) and minimum 12 month follow up were included. Morphologic measurements of butterfly fragments were performed to measure location, size, and displacement, and mRust scores at final follow up were calculated. Outcome measures were surgery to promote union, and mRust scores.

RESULTS

A total of 99 patients were included with 21 patients requiring revision surgery to promote union. Thirty six patients had open fractures and 77% of patients were male with a mean age of 34 (range: 12-80). Average follow up was 19 months (3 months - 12 years). The most common location of the butterfly fragment was the anterior cortex (42%), with a mean length of 7.8cm (SD: 3.3) and width of 1.8cm (SD: 0.5cm). At final follow-up 37% of fractures had persistent lucency without callus at the site of the butterfly while only 31% of fractures had remodeled cortex. Average time to complete healing was 13.3 months. Open fractures with butterfly fragments were more likely to go on to nonunion than closed (44% vs 9.2%, p=<0.001). The length of the butterfly fragment was not different between the union and nonunion groups (7.7 vs 7.5, P=0.42).

CONCLUSIONS

Open tibial shaft fractures with a butterfly fragment have a high risk of nonunion. Further research may seek to determine if adjunct treatment of butterfly fragments (ie inter-fragmentary compression) in the acute setting could improve healing rates.

Bone Healing Gone Wrong: Pathological Fracture Healing and Non-Unions-Overview of Basic and Clinical Aspects and Systematic Review of Risk Factors

Bone healing is a multifarious process involving mesenchymal stem cells, osteoprogenitor cells, macrophages, osteoblasts and -clasts, and chondrocytes to restore the osseous tissue. Particularly in long bones including the tibia, clavicle, humerus and femur, this process fails in 2-10% of all fractures, with devastating effects for the patient and the healthcare system. Underlying reasons for this failure are manifold, from lack of biomechanical stability to impaired biological host conditions and wound-immanent intricacies. In this review, we describe the cellular components involved in impaired bone healing and how they interfere with the delicately orchestrated processes of bone repair and formation. We subsequently outline and weigh the risk factors for the development of non-unions that have been established in the literature. Therapeutic prospects are illustrated and put into clinical perspective, before the applicability of biomarkers is finally discussed.

EGFL7 Secreted By Human Bone Mesenchymal Stem Cells Promotes Osteoblast Differentiation Partly Via Downregulation Of Notch1-Hes1 Signaling Pathway

BACKGROUND

Epidermal growth factor-like domain protein 7 (EGFL7) is a secreted protein that is differentially expressed in the bone microenvironment; however, the effect of EGFL7 on the osteogenesis of human bone marrow mesenchymal stem cells (hBMSCs) is largely unknown.

METHODS

EGFL7 expression in the fracture microenvironment was analyzed based on the Gene Expression Omnibus (GEO) database. Knockdown of EGFL7 by small interfering RNA (siRNA) and in vitro stimulation with recombinant human EGFL7 (rhEGFL7) protein were used to assess alterations in downstream signaling and changes in the osteogenic differentiation and proliferation of hBMSCs. A γ-secretase inhibitor was used to further explore whether inhibition of Notch signaling rescued the osteogenic-inhibitory effect of EGFL7 knockdown in hBMSCs. A femoral defect model was established to verify the effect of recombinant mouse EGFL7 on bone healing in vivo.

RESULTS

EGFL7 expression increased during hBMSC osteogenesis. Knockdown of EGFL7 impaired hBMSC osteogenesis and activated Notch1/NICD/Hes1 signaling. rhEGFL7 promoted hBMSC osteogenesis and downregulated Notch1 signaling. The osteoblast-inhibitory effect of EGFL7 knockdown was rescued by Notch1 signaling inhibition. Recombinant EGFL7 led to enhanced bone healing in mice with femoral defects.

CONCLUSIONS

EGFL7 promotes osteogenesis of hBMSCs partly via downregulation of Notch1 signaling.

CXCR4 mediates the effects of IGF-1R signaling in rodent bone homeostasis and fracture repair

Non-union fractures have considerable clinical and economic burdens and yet the underlying pathogenesis remains largely undetermined. The fracture healing process involves cellular differentiation, callus formation and remodeling, and implies the recruitment and differentiation of mesenchymal stem cells that are not fully characterized. C-X-C chemokine receptor 4 (CXCR4) and Insulin-like growth factor 1 receptor (IGF-1R) are expressed in the fracture callus, but their interactions still remain elusive. We hypothesized that the regulation of CXCR4 by IGF-1R signaling is essential to maintain the bone homeostasis and to promote fracture repair. By using a combination of in vivo and in vitro approaches, we found that conditional ablation of IGF-1R in osteochondroprogenitors led to defects in bone formation and mineralization that associated with altered expression of CXCR4 by a discrete population of endosteal cells. These defects were corrected by AMD3100 (a CXCR4 antagonist). Furthermore, we found that the inducible ablation of IGF-1R in osteochondroprogenitors led to fracture healing failure, that associated with an altered expression of CXCR4. In vivo AMD3100 treatment improved fracture healing and normalized CXCR4 expression. Moreover, we determined that these effects were mediated through the IGF-1R/Insulin receptor substrate 1 (IRS-1) signaling pathway. Taken together, our studies identified a novel population of endosteal cells that is functionally regulated through the modulation of CXCR4 by IGF-1R signaling, and such control is essential in bone homeostasis and fracture healing. Knowledge gained from these studies has the potential to accelerate the development of novel therapeutic interventions by targeting CXCR4 signaling to treat non-unions.

Are pre- and postoperative true translational and angular displacement predictive of nonunion after intramedullary nail fixation of tibial shaft fractures?

PURPOSE

To determine if there is an association between pre-/postoperative translational and angular displacement with nonunion after intramedullary nail (IMN) fixation of tibial shaft fractures.

METHODS

Retrospective review of 120 patients with tibial shaft fractures undergoing IMN at an urban level-one trauma center was performed. Demographics, injury characteristics, and pre-/postoperative translational and angular fracture displacement in the coronal and sagittal planes were recorded. True fracture translational and angular displacement (TTD and TAD) were calculated by combining sagittal and coronal displacement utilizing the Pythagorean theorem.

RESULTS

10.8% of patients (n = 13) developed nonunion with remaining patients serving as the control. Groups were similar across age, sex, and BMI. Univariate analysis revealed no difference in pre-/postoperative TAD between nonunion and union groups and an increased preoperative TTD (median difference (MD): 6.2 mm, CI: 1.4-10.8 mm) and postoperative TTD (MD: 1.8 mm, CI: 0-3.7 mm) in the nonunion group. On multivariate analysis, however, only tobacco use and type 2 or 3 open fractures were associated with nonunion (OR: 5.1, CI: 1.2-22.8 and OR: 4.9, CI: 1.2-19.2, respectively).

CONCLUSION

True translational and angular displacement of tibial shaft fractures before and after IMN fixation were not independently associated with nonunion. Tobacco use and type 2 or 3 open fracture are independent factors for nonunion.

Combination of radiographic apparent bone gap and nonunion risk determination score improves accuracy of prediction of tibial shaft delayed union

BACKGROUND

There is a need for a novel therapeutic strategy for an earlier prediction of long bone union failure as compared to previous methodologies. This study aimed to determine whether a combination of two diagnostic tools would result in a more accurate diagnosis of delayed union.

METHODS

The inclusion criteria were as follows: patients with tibial shaft fracture who underwent treatment with intramedullary nailing (IMN) as definitive internal fixation (IF). The study included a total of 114 patients with 116 tibial shaft fractures treated with IMN as definitive IF. Radiographic apparent bone gap (RABG) and nonunion risk determination score (NURDS) can be used to predict nonunion. However, this study aimed to determine whether combination of RABG and NURDS could help deduce a more accurate prediction of delayed union.

RESULTS

The union rate was found to be 85% (99 fractures), the delayed union rate was found to be 15% (17 fractures), and the rate of nonunion requiring additional surgical intervention was estimated to be 4% (5 out of the 17 delayed union cases). Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of RABG were found to be 82.3%, 76.0%, 36.8%, and 96.2%, respectively, when an RABG cutoff value of 5.0 mm was applied to our patient cohort. The sensitivity, specificity, PPV, and NPV of NURDS were found to be 47.1%, 82.0%, 30.8%, and 90.1%, respectively, when a NURDS cutoff value of 8.0% was applied to our patient cohort. When RABG and NURDS were above their respective cutoff values, the sensitivity and PPV were estimated to be 90.0% and 56.3%, respectively. When RABG and NURDS were below their respective cutoff values, the specificity and NPV were estimated to be 90.1% and 98.5%, respectively.

CONCLUSIONS

The combination of RABG and NURDS evaluation immediately after surgery helps surgeons identify patients who are at a high risk of delayed union, facilitating careful monitoring of these patients and consideration of additional treatments.

The Effect of Vitamin D Supplementation for Bone Healing in Fracture Patients: A Systematic Review

While most literature on vitamin D supplementation in fracture patients focuses on fracture prevention, the effect of vitamin D on bone healing is a much less studied concept. The primary aim of this systematic review was to assess whether vitamin D supplementation in fracture patients improves clinical or radiological union complications. The secondary aims were to assess supplementation effect on patient functional outcome scores and bone mineral density (BMD). A systematic search of all relevant articles was performed using the following databases: MEDLINE, Embase, Google Scholar, and Web of Science. The population selection included human patients with a fresh fracture treated conservatively or operatively. The intervention included any form of vitamin D supplementation, compared to no supplementation or a placebo. The primary outcomes assessed were clinical or radiological union rates or complications arising from the nonunion. The secondary outcomes assessed were functional outcome scores, BMD scores after treatment, and pain scores. A total of fourteen studies, assessing a total of 2734 patients, were included. Eight studies assessed the effect of vitamin D on clinical or radiological union. Five studies reported no significant difference in complication rates when supplementing fracture patients. Alternatively, three studies reported a positive effect with supplementation between the groups. One of these studies found a difference only for early orthopaedic complications (<30 days), but no differences in late complications. The other two studies found significant differences in clinical union; however, no changes were observed in radiological union. Six studies investigated functional outcome scores after supplementation. Four of these studies found no significant differences between most functional outcome scores. Only three studies reported BMD outcomes, one of which found limited effect on total hip BMD. The overall findings are that vitamin D alone does little to influence fracture healing and subsequent union rates or functional outcome. The studies suggestive of a positive effect were generally of a lower quality. Further high quality RCTs are needed to justify routine supplementation at the time of fracture.

Self-assembled microtissues loaded with osteogenic MSCs for in vivo bone regeneration

Bone regeneration strategies based on mesenchymal stem cell (MSC) therapy have received widespread attention. Although MSC incorporation into bone scaffolds can help with the repair process, a large number of studies demonstrate variable effects of MSCs with some noting that the inclusion of MSCs does not provide better outcomes compared to unseeded scaffolds. This may in part be related to low cell survival following implantation and/or limited ability to continue with osteogenic differentiation for pre-differentiated cells. In this study, we incorporated MSCs into gelatin microcryogels to form microtissues, and subjected these microtissues to osteogenic induction. We then mixed as-formed microtissues with those subjected to 6 days of osteogenic induction in different ratios, and investigated their ability to induce in vitro and in vivo osteogenesis during self-assembly. Using a full-thickness rat calvarial defect model, we found that undifferentiated and osteogenically induced microtissues mixed in a ratio of 2:1 produced the best outcomes of bone regeneration. This provides a new, customizable cell-based therapeutic strategy for in vivo repair of bone defects.

A scoping review of operative and non-invasive management in the treatment of non-unions

INTRODUCTION

Non-union occurs when a fracture fails to adequately heal, and requires additional intervention to achieve union. The purpose of this scoping review is to provide a high-level overview of the existing non-union management literature. This review aims to highlight the current literature on non-union management, as well as identify key areas that require future research to provide a better understanding of potential non-union management strategies.

METHODS

This study utilized the scoping review framework from Arksey and O'Malley All relevant literature on non-union management was systematically searched for within the OVID Medline, OVID Embase, and Web of Science databases. As a scoping review, this study aimed to identify the high-level trends in non-union literature. This was assessed through a visual and numerical summary of the general themes in non-union literature, as well as the timeline in which these trends have occurred.

RESULTS

The literature search identified 8081 articles, of which 2210 articles were included. There is a large body of evidence for various surgical treatment options for non-union. The literature suggests healing rates between 80 and 100 percent for commonly utilized surgical procedures, such as plating with bone graft for long bones. Despite these beneficial healing rates, the requirement of a surgery creates a large socioeconomic burden. The possibility for bone growth stimulator (BGS) options to achieve non-union healing rates in a similar realm as surgical options suggests that the use of a BGS may be a beneficial option prior to surgical intervention, as this would potentially reduce the number of patients who would otherwise require surgery.

CONCLUSION

A large body of evidence exists on non-union management, which is largely comprised of case series and reports. The most commonly assessed non-unions include the tibia, wrist, and femur. Bone grafting, plating, and nailing are the most investigated treatment options. BGS are a non-operative treatment options for non-union that provide similar healing rates to surgical options in certain indications within initial observational data. BGS are a potential option for non-operative management of non-unions to reduce socioeconomic burdens of surgical intervention, with a need for further high-quality investigation in this therapeutic area.

Outcomes of Intramedullary Nailing and External Fixation of Open Tibial Fractures: Three to Five-Year Follow-up of a Randomized Clinical Trial

BACKGROUND

While surgeons in low and middle-income countries have increasing experience with intramedullary nailing (IMN), external fixation (EF) continues to be commonly used for the management of open tibial fractures. We examined outcomes with extended follow-up of the participants enrolled in a clinical trial comparing these treatments.

METHODS

Adults who were ≥18 years old with acute AO/OTA type-42 open tibial shaft fractures were randomly assigned to statically locked, hand-reamed IMN or uniplanar EF. These participants were reevaluated 3 to 5 years after treatment. The primary outcome was death or reoperation for the treatment of deep infection, nonunion, or malalignment. Unresolved complications such as persistent fracture-related infection, nonunion, or malalignment were collected and analyzed. Secondary outcomes included the EuroQol-5 Dimension-3 Level (EQ-5D-3L) questionnaire, the Function IndeX for Trauma (FIX-IT) score, radiographic alignment, and the modified Radiographic Union Scale for Tibial fractures (mRUST).

RESULTS

Of the originally enrolled 240 participants,126 (67 managed with IMN and 59 managed with EF) died or returned for follow-up at a mean of 4.0 years (range, 2.9 to 5.2 years). Thirty-two composite primary events occurred, with rates of 23.9% and 27.1% in the IMN and EF groups, respectively. Six of these events (3 in the IMN group and 3 in the EF group) were newly detected after the original 1-year follow-up. Unresolved complications in the form of chronic fracture-related infection or nonunion were present at long-term follow-up in 25% of the participants who sustained a primary event. The EQ-5D-3L index scores were similar between the 2 groups and only returned to preinjury levels after 1 year among patients without complications or those whose complications resolved.

CONCLUSIONS

This observational study extended follow-up for a clinical trial assessing IMN versus EF for the treatment of open tibial fractures in sub-Saharan Africa. At a mean of 4 years after injury, fracture-related infection and nonunion became chronic conditions in nearly a quarter of the participants who experienced these complications, regardless of reintervention.

LEVEL OF EVIDENCE

Therapeutic Level IV . See Instructions for Authors for a complete description of levels of evidence.

Smart fracture plate for quantifying fracture healing: Preliminary efficacy in a biomechanical model

The diagnosis of fracture nonunion following plate osteosynthesis is subjective and frequently ambiguous. Initially following osteosynthesis, loads applied to the bone are primarily transmitted through the plate. However, as callus stiffness increases, the callus is able to bear load proportional to its stiffness while forces through the plate decrease. The purpose of this study was to use a "smart" fracture plate to distinguish between phases of fracture healing by measuring forces transmitted through the plate. A wireless force sensor and small adapter were placed on the outside of a distal femoral locking plate. The adapter converts the slight bending of the plate under axial load into a transverse force which is measurable by the sensor. An osteotomy was created and then plated in the distal femur of biomechanical Sawbones. Specimens were loaded to simulate single-leg stance first with the osteotomy defect empty (acute healing), then sequentially filled with silicone (early callus) and then polymethyl methacrylate (hard callus). There was a strong correlation between applied axial load and force measured by the "smart" plate. Data demonstrate statistically significant differences between each phase of healing with as little as 150 N of axial load applied to the femur. Forces measured in the plate were significantly different between acute (100%), early callus (66.4%), and hard callus (29.5%). This study demonstrates the potential of a "smart" fracture plate to distinguish between phases of healing. These objective data may enable early diagnosis of nonunion and enhance outcomes for patients.

Contemporary management of aseptic diaphyseal tibia non-unions - A systematic review

INTRODUCTION

Tibia fractures are the most common long bone injuries encountered in the trauma population. The majority are treated successfully but non-union remains a common complication. A systematic review of current evidence regarding the management for aseptic diaphyseal tibial non-unions was undertaken.

METHODS

A systematic review using the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA), was conducted.

RESULTS

A total of 632 publications were screened for inclusion. Full text review of 91 studies resulted in 26 publications being retained for final review. The majority of patients included in the studies either underwent exchange nailing (n=315) or primary intramedullary nailing (n=174) with respective union rates of 88% and 95% being achieved. The highest union rate (97%) was achieved with the use of fine wire external fixation. The major adjuvant treatment modalities were fibula osteotomies (n=372; 41%), fixation dynamization (n=208; 23%) and bone grafting (n=183; 20%).

CONCLUSION

The lack of standardization in reporting of outcomes and the diversity of management strategies employed precludes definitive conclusions or recommendations. Further research is required to ascertain the ideal treatment strategy in the management of aseptic tibial diaphyseal non-unions.

LEVEL OF EVIDENCE

IV.

Comparison of outcomes and operative course between septic and aseptic nonunion in long bones

PURPOSE

The treatment of nonunion of long bones is difficult particularly in the presence of infection, which often involves staged surgical management. There is limited literature to compare the post operative course and outcomes of patients treated for septic versus aseptic nonunion. Thus, the purpose of this study was to determine if a difference exists between the number of surgical procedures, time to union, and rate of successful union for these two groups.

METHODS

A retrospective cohort study was performed at a single tertiary care center. Patients suffering nonunion of the humerus, tibia and femur were included. Patient demographic data and characteristics of the post operative course were collected to include number and reason for repeat operations, antibiotic course, time to union, and development of a successful union.

RESULTS

About 28 of 122 patients had septic nonunion. After diagnosis of nonunion, the septic group averaged 3.9 surgeries compared to 1.5 in the aseptic group (p < 0.001). There was no difference in the rate of successful union (79.8% versus 85.7%; p = 0.220), though the septic group took 129 days longer on average for successful union. (376 versus 247; p = 0.018).

CONCLUSION

Septic nonunion of long bones is associated with the need for significantly more operations as well as time to union, though union rates remain similar. The identification of infection is critical for both the appropriate treatment as well as counseling patients on the expected post operative course.

The use of heparin/polycation coacervate sustain release system to compare the bone regenerative potentials of 5 BMPs using a critical sized calvarial bone defect model

Nonunion following bone fracture and segmental bone defects are challenging clinical conditions. To combat this clinical dilemma, development of new bone tissue engineering therapies using biocompatible materials to deliver bone growth factors is desirable. This aim of this study is to use a heparin/polycation coacervate sustained-release platform to compare 5 bone morphogenetic proteins (BMPs) for promoting bone defect healing in a critical sized calvarial defect model. The in vitro 3D osteogenic pellet cultures assays demonstrated that BMPs 2, 4, 6, 7 and 9 all enhanced mineralization in vitro compared to the control group. BMP2 resulted in higher mineralized volume than BMP4 and BMP6. All BMPs and the control group activated the pSMAD5 signaling pathway and expressed osterix (OSX). The binding of BMP2 with coacervate significantly increased the coacervate average particle size. BMP2, 4, 6, & 7 bound to coacervate significantly increased the Zeta potential of the coacervate while BMP9 binding showed insignificant increase. Furthermore, using a monolayer culture osteogenic assay, it was found that hMDSCs cultured in the coacervate BMP2 osteogenic medium expressed higher levels of RUNX2, OSX, ALP and COX-2 compared to the control and BMPs 4, 6, 7 & 9. Additionally, the coacervate complex can be loaded with up to 2 μg of BMP proteins for sustained release. In vivo, when BMPs were delivered using the coacervate sustained release system, BMP2 was identified to be the most potent BMP promoting bone regeneration and regenerated 10 times of new bone than BMPs 4, 6 & 9. BMP7 also stimulated robust bone regeneration when compared to BMPs 4, 6 & 9. The quality of the newly regenerated bone by all BMPs delivered by coacervate is equivalent to the host bone consisting of bone matrix and bone marrow with normal bone architecture. Although the defect was not completely healed at 6 weeks, coacervate sustain release BMPs, particularly BMP2 and BMP7, could represent a new strategy for treatment of bone defects and non-unions.

A major trauma centre experience with gentamicin-coated tibial intramedullary nails (ETN PROtect™) in acute primary open fracture fixation and complex revision surgery

PURPOSE

Fracture-related infections (FRI) following intramedullary nailing for tibial shaft fractures remain challenging to treat with associated high patient morbidity and health care costs. Recently, antibiotic-coated nails have been introduced as a strategy to reduce implant related infection rates in high-risk patients. We present the largest single-centre case series on ETN PROtect® outcomes reporting on fracture union, infection rates and treatment complications.

METHODS

Fifty-six adult patients underwent surgery with ETN PROtect® between 01/09/17 and 31/12/20. Indications consisted of acute open fractures and complex revision cases (previous FRI, non-union surgery and re-fracture) with a mean of three prior surgical interventions. We report on patient demographics, union rates and deep infection. Minimum follow-up was one year.

RESULTS

One (1.8%) patient developed a deep surgical infection and associated non-union requiring further surgery. In addition, we identified three cases (5.4%) of aseptic non-union following facture treatment with ETN PROtect®. Of the five patients who underwent staged complex revision surgery for established FRI with ETN PROtect®, all had treatment failure with ongoing symptoms of deep infection requiring implant removal and further treatment.

CONCLUSION

Use of the ETN PROtect® nail in high-risk patients (open fractures and those initially treated with external fixation) and in those patients with aseptic non-unions, demonstrates promising outcomes in the prevention of implant-related infection. In our limited series we have failed to observe any benefit over uncoated nails, when used in treating cases of previously established FRI/osteomyelitis and would therefore advise caution in their use, especially in view of the high cost.